Troubles of an Old Space Station

Troubles of an Old Space Station

Article excerpt

This week's computer problems aboard the International Space
Station (ISS) highlight one of the challenges facing station
partners as they strive to complete the orbiting outpost by 2010:
dealing with aging components and ensuring enough spare parts are on
hand to allow prompt fixes to problems that threaten the crew or the
station.

On Wednesday, two computer systems on the Russian segment of the
orbiting outpost failed as astronauts from the visiting space
shuttle Atlantis were reconfiguring solar arrays. The computers help
control the space station's orientation in space and run equipment
that provides oxygen and scrubs carbon dioxide from the air that
crew members breathe.

NASA officials expressed confidence that the problem would be
solved quickly. But the computer outage did prompt them to make
plans to extend Atlantis's stay at the station for an extra two
days. This would give Russian engineers extra time to deal with the
problem if they needed it, since the shuttle could be used to help
keep the station in its proper orbit.

"We have plenty of resources, so we have plenty of time to sort
this out," said ISS program manager Michael Suffredini during a
briefing late Wednesday evening.

By Thursday morning, the situation "was looking a lot better than
when we went to bed last night," added John Ira Petty, a spokesman
at the Johnson Space Center in Houston. The Russians had re-
established communications with one of the two systems, which
provides overall command and control for the Russian segments. From
there, it would be a matter of "cleanup and troubleshooting" to
determine why the computers failed to reboot as planned after they
went down, he said.

Yet to some analysts, such problems are likely to crop up with
increasing frequency as time passes. While much attention has
focused on the new elements the shuttle has been delivering to the
station, those elements are being bolted to a core whose key
components have been in orbit since the late 1990s. Some parts
exceed their original design lives.

"In many cases, these things work just fine," says Keith Cowing,
editor of the on-line service NASA Watch and a former payload-
integration specialist with the space station program. "But the
system is aging, and it's not always aging smoothly."

He notes, for instance, that the core of the Russian command
module was originally built as a replacement element for the Mir
space station, which ended its career in 2001. "It was sitting on
the ground years before it flew, and it's been up for six or seven
years now," he says. "Computers in the US segments use radiation-
hardened 386 processors," which today's computers industry has long
since left behind. "Who knows what the Russians are using," he says.

The issue of spare parts - at least as it pertains to the US -
came up earlier this year in a report from the International Space
Station Independent Safety Task Force. …